Multi-zone food holding bin

ABSTRACT

A multi-zone food holding bin has a continuous food supporting surface with multiple food holding zones. Each food holding zone is independently controllable so that different food temperatures may be maintained in adjacent food holding zones.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/403,349, filed May 3, 2019, which is a continuation of U.S. patentapplication Ser. No. 15/984,760, filed May 21, 2018, which is acontinuation of U.S. patent application Ser. No. 15/134,380, filed Apr.20, 2016, which are incorporated herein by reference in their entiretyand made a part hereof.

BACKGROUND

Often the success of a restaurant depends, at least in part, on howquickly customers can be served with ordered food items and also on thequality of the food items when served. If the rate of food preparationequals the rate at which the food is ordered and sold, a restaurant cantheoretically have freshly-prepared foods ready to serve for customersas they arrive. Since it is not always possible to match food productionwith customer ordering rates, and since certain fast food restaurantcustomers expect to receive their ordered food items quickly, many fastfood restaurants prepare various food items in advance and keep themready for sale until a customer arrives and purchases a pre-cooked fooditem.

To facilitate the food holding process, holding bins or holding ovensare often used to keep the food warm. Known holding bins can allow acooked food item to be inserted from one side and taken from theopposite side whereby food preparers add food to the holding bin on oneside and food servers on the opposite side take food from the holdingbin. Food holding bins in which the cooked food item is inserted andremoved from the same side are also known. The food items in the holdingbins are kept warm by heating elements. However, food holding time inknown holding bins or ovens is somewhat limited, generally less than 15or 20 minutes before the food item must be discarded. As a result,restaurants can only keep a limited amount of pre-cooked food items onhand and often a significant amount of the pre-cooked food items must bediscarded before they are sold, resulting in additional costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multi-zone food holding bin;

FIG. 2 is a front elevational view of the multi-zone food holding bin ofFIG. 1 ;

FIG. 3 is a rear elevational view of the multi-zone food holding bin ofFIG. 1 ;

FIG. 4A is a partially cut-away top perspective view of an alternateembodiment of a multi-zone food holding bin, and FIG. 4B is a close upof a shelf portion of the multi-zone food holding bin from circle 4B inFIG. 4A;

FIG. 5 is a partially cut-away bottom perspective view of the foodholding bin of FIG. 4 ; and

FIG. 6 is a partially cutaway top perspective view of yet anotheralternate embodiment of a multi-zone food holding bin.

DETAILED DESCRIPTION

Turning now to FIGS. 1-3 , a multi-zone food holding bin 10 includes twoseparate food holding compartments 50. Additional food holdingcompartments 50 may also be included as explained in further detailbelow. Each separate food holding compartment 50 includes two or moreseparate food holding zones, for example, as illustrated in FIGS. 1-3 ,a first food holding zone 57 a and a second food holding zone 57 b. Eachfood holding zone 57 a, 57 b may include two food holding bays. Forexample, the first food holding zone 57 a may include a first foodholding bay 51 a and a second food holding bay 51 b. The second foodholding zone 57 b may include a third food holding bay 51 c and a fourthfood holding bay 51 d. Each food holding bay 51 a, 51 b, 51 c, 51 d iscapable of receiving a single food holding tray 27 and/or a single lid21, as illustrated in the third food holding bay 51 c in FIG. 2 . Thefood holding bays 51 a, 51 b, 51 c, and 51 d are illustrated as beingseparated from one another by a dashed line in FIGS. 1-3 . The dashedlines are for illustration only. The food holding bays need not havetheir boundaries identified with any sort of line or other indicia infood holding compartment 50. Each food holding zone 57 a, 57 b can beconfigured to maintain a different food holding temperature,advantageously allowing the operator to hold different food productswith different heating requirements in the same food holding compartment50, thereby permitting increased energy efficiencies to be realized andpotentially reducing the space requirements for holding different foods.For example, a first food product can be held in the first food holdingbay 51 a of the first

food holding zone 57 a and a second food product, which may be the sameas the first food product or different from the first food product aslong as both food products have substantially the same temperaturerequirements, can be held in the second food holding bay 51 b of thefirst food holding zone 57 a. Both the first food holding bay 51 a andthe second food holding bay 51 b are held at a first temperature byindependently controllable upper and lower heating elements.A third food product can be held in the third food holding bay 51 c ofthe second food holding zone 57 b and a fourth food product, which maybe the same as the third food product or different from the third foodproduct as long as both food products have substantially the sametemperature requirements, may be held in the fourth food holding bay 51d of the second food holding zone 57 b. Both the third food holding bay51 c and the fourth food holding bay 51 d are held at a secondtemperature by independently controllable upper and lower heatingelements.Because the heating elements used to heat the second food holding zone57 b are different from those used to heat the first food holding zone57 a, the second temperature of the second food holding zone 57 b iscapable of being independently set to be different from the firsttemperature of the first food holding zone 57 a. Suitable heatingelements are illustrated with respect to the embodiment shown in FIGS.4A, 4B, and 5 . This can be particularly useful for restaurants duringlower demand times (as fewer food holding bins are needed to hold largernumbers of different food items than previously) and also for smallerrestaurants and retail operations (as space constraints can be met moreeasily).

In one embodiment of the bin 10, all of the compartments 50 are heated.In another embodiment, some compartments 50 may be refrigerated whileother compartments 50 are heated. In yet another embodiment, one or morecompartments 50 can be selectively heated or refrigerated.

The bin 10 includes a chassis 15. As illustrated, the chassis 15includes a top panel 20, a bottom panel 25, a left-side panel 30, aright side panel 35, an open front face 40 and an open rear face 45.When the rear face 45 is open and uncovered, food items can be insertedby a first operator responsible for initial food preparation into one ofthe faces 40, 45 and passed through to and removed from the other of thefaces 40, 45 by a second operator responsible for final foodpreparation, for example, a second operator responsible for packagingand customization of a food product for serving to the ultimatecustomer. In another embodiment, the rear face 45 may be “closed” andprovided by a rear panel such that access into the bin 10 is onlyprovided by the open front face 40. The panels may be insulated toreduce heat transfer between the interior of the bin 10 and theatmosphere surrounding the bin 10.

The bin 10 illustrated in FIG. 1 is sized, shaped and arranged to havetwo compartments 50, however, the bin 10 can have any number ofcompartments 50, including a single compartment 50. For clarity, the twocompartments 50 depicted in FIGS. 1-3 are denominated using the lettersA and B. The “A” compartment is the top or uppermost compartment 50 andthe “B” compartment is the bottom or lower-most compartment 50.

In the embodiment illustrated in FIG. 1 , the top or “A” compartment isdefined by the left and right sidewalls 30 and 35, the chassis top panel20 and a first or upper-most shelf 52.

Compartment “B” is defined by the two sidewalls 30 and 35, the first orupper-most shelf 52, and the chassis bottom panel 25. In bin embodimentshaving only one compartment 50, the single compartment is defined byopposing, left and right sidewalls 30 and 35, a chassis top panel 20 anda chassis bottom panel 25. For brevity, bin construction and operationis described with regard to a bin 10 having two compartments 50 in FIGS.1-3 . However, other embodiments may have more than two compartments 50or less than two compartments 50. For example, the embodimentsillustrated in FIGS. 4A, 4B, 5, and 6 have four compartments 50. Again,other configurations are also possible.

The shelf 52, which partially defines the compartments 50, is planar orat least substantially planar and supported in the chassis 15 atopposing side ends by the two chassis side walls 30 and 35. The shelf 52includes a planar and continuous top surface, which forms a planar andcontinuous bottom surface 53 of the upper compartment 50. The planar andcontinuous bottom surface 53 of the upper compartment 50 is configuredto support food items (as used herein, the term “food item” includes butis not limited to containers or trays containing food products such ascooked protein patties, fried foods, and the like). In the illustratedembodiment, food items can be placed onto the planar and continuousbottom surface 53 and removed from the planar and continuous bottomsurface 53 through the open front face 40 or through the open rear face45. Because the bottom surface 53 is planar and continuous andsubstantially free of any dividing walls or other structure between theholding zones 57 a, 57 b, and more particularly between the food holdingbays 51 a, 51 b, 51 c, and 51 d, cleaning of the bottom surface 53 canbe easily accomplished.

A face plate or bezel 92 is generally attached to the front of thechassis 15. For example, the bezel can be attached to the sidewalls 30and 35 of the chassis 15 so as to be disposed underneath a top surfaceof the shelf 52. In bin embodiments having only one compartment 50, thebezel 92 may be attached to either of the chassis top or bottom panels20, 25 of the bin 10. In the illustrated embodiment of FIGS. 1-3 , thebezel 92 is set forward from the shelf 52 by a space 55. The space 52forms a slot in which one or more latches 23 translate and/or rotatefrom a locked/default position to an unlocked position so as to releaselids held in lid holding ledges 31 as will be discussed further below.

The bezels 92 may include information displays and/or controls, whichare collectively identified by reference numeral 93. Although thechassis 15 can include panels concealing the heat generating deviceslocated within a shelf, the bezel 92 also can conceal heating elements,which are located within the shelf 52, such that a separate panel is notpresent.

Each food holding bay 51 a, 51 b, 51 c, 51 d may include a dedicateddisplay and/or control 93 a, 93 b, 93 c, 93 d, respectively. While eachdedicated display and/or control 93 a, 93 b, 93 c, 93 d may displayand/or control the temperature within individual food holding bays 51 a,51 b, 51 c, 51 d, the food holding bays within a particular food holdingzone (51 a and 51 b within 57 a; 51 c and 51 d within 57 b) have thesame temperature setting. The dedicated display and/or controls 93 a, 93b, 93 c, 93 d, may also display additional information about the fooditem stored in the food holding bay 51 a, 51 b, 51 c, 51 d. For example,while the temperature in the first food holding bay 51 a and the secondfood holding bay 51 b is the same (because both food holding bays 51 a,51 b are located within a single food holding zone 57 a), the displayand/or control 93 a, 93 b may indicate that the first food holding bay51 a has a first food item (such as sausage) while the second foodholding bay 51 b has a second food item (such as eggs). In theembodiment illustrated in FIGS. 1-3 , the display and control 93 a, 93b, 93 c, and 93 d can display the particular food item, the temperaturesetpoint of a respective food holding bay 51 a, 51 b, 51 c, 51 d, alongwith other information about the food item stored in the food holdingbay 51 a, 51 b, 51 c, 51 d, such as the food holding bay is ready toreceive food items, the food items in the food holding bay should bediscarded, the food items in the food holding bay are older and shouldbe used first relative to the same food items contained in another foodholding bay, the food items in the food holding bay are newer relativeto the same food items contained in another food holding bay such thatthe food items contained in the other food holding bay should be usedfirst, it is time to cook more food product. Moreover, the heatingelements for each food holding zone 57 a, 57 b can be controlled by thedisplays and/or controls 93 a, 93 b, 93 c, 93 d to maintain thetemperature setpoint of the respective food holding zones 57 a, 57 b.The displays and/or controls 93 a, 93 b, 93 c, 93 d may be groupedtogether (i.e., arranged horizontally beneath the respective foodholding bay 51 a, 51 b, 51 c, 51 d) in the bezel 92 for a correspondingcompartment 50. In the embodiment illustrated in FIGS. 1-3 , a singlebezel 92 is used to provide the display and/or control elements for twovertically adjacent compartments 50, but of course discrete bezels canalso be used. The displays and/or controls 93 a, 93 b, 93 c, 93 d thuscan provide a user graphical interface to one or more controllers (notshown) for the bin. A temperature control interface panel 95 may also beprovided to control the temperatures of the food holding zones 57 a, 57b.

Each food holding bay 51 a, 51 b, 51 c, 51 d may be sized to receive anindividual food holding tray 27 and lid 21 (see FIG. 2 where the tray 27is illustrated in broken lines). In order to conveniently store the lid21, each food holding bay 51 a, 51 b, 51 c, 51 d may also include adedicated lid holding shelf 31 that is sized to receive and store thelid 21 when the lid 21 is desired for use in combination with a foodholding tray 27, such as when protein patties are contained within thetray 27. Generally, a top surface 27 a of a food holding tray 27, whenreceived in the lid holding shelf 31, is substantially flush with a topsurface of the lid holding shelf 31 such that when the tray 27 isdisposed in the food holding bay 51 c, the tray 27 can be in contactwith and engaged by the lid 21 in the lid holding shelf 31 so as toretain moisture within the tray 27-lid 21 assembly. In some embodiments,the lid holding shelf 31 may be provided by formed sheet metal. In otherembodiments, the lid holding shelf 31 may be provided by a wire form.Other structures are also possible.

Adjacent to each lid holding shelf 31 is one or more latches 23 havingan open center portion. In the embodiment illustrated in FIGS. 1-3 ,each food holding zone 57 a, 57 b includes a single dedicated latch 23that selectively secures lids 21 in the food holding shelves 31 in eachfood holding bay 51 a, 51 b, 51 c, 51 d. In the illustrated embodiment,the latches 23 have a round or curved body 29 that is rotatable and/ortranslatable (because of the open center) about a retaining element suchas a pin or screw (not shown). In other embodiments, the latches 23 mayhave straight or angled outer surfaces that form other shapes, such as asquare, a pentagon, a hexagon, or any other polygonal shape. The latches23 may be disposed adjacent an opening into the food holding compartment50 above the lid holding shelf 31. In one example, the latches 23 may becaptured on a cylindrical retaining element between the chassis 15 and atop of the food holding compartment 50 above the lid holding shelf 31.In other embodiments, one or more washers (not shown), such as metal,nylon, or plastic washers, may be disposed on the cylindrical retainingelement to space the latches 23 apart from the bezel 92 and the shelf 52to prevent metal galling and/or to reduce friction between the latches23 and the bezel 92 or shelf 52 to ease actuation of the latches 23.

The round body 29 may be oriented substantially parallel to a front faceof the chassis 15 or the bezel 92 in a locked or default position, asillustrated by reference numeral 23 a, which prevents inadvertentremoval of a lid 21 from the lid holding shelf 31 when a tray 27 iswithdrawn. The latch 23 is in its default or locked position simplybecause of gravity, thus re-positioning the latch to an unlocked stateadvantageously requires simply overcoming the weight of the latch 23 bytranslational and/or rotational movement. The round body 29 may berotated and/or translated upwards relative to the bezel 92 or lidholding shelf 31 from the locked or default position to an unlockedposition, as illustrated by the dotted lines referencing latch 23between food holding bay 51 a and food holding bay 51 b in FIG. 1 ; thisrotational and/or translational movement of the latch 23 about theretaining element allows facile insertion or removal of a lid 21 to/fromthe lid holding shelf 31. The round body 29 may be mounted on aretaining element such as a pin or a screw (not shown), which retainsthe round body 29 and allows the round body 29 to translate along theopen center portion and/or to at least partially rotate about the pinwhen the round body 29 translates. The lid holding shelf 31 also allowsthe food holding compartment 50 to have the planar and continuous bottomsurface 52 by storing the lids 27 a in an elevated position, with thelid holding shelf 31 being suspended above the

continuous bottom surface 52, typically by fixedly attaching a base ofthe shelf to a top surface of the food holding compartment 50 at one ormore positions. Such continuous planar and continuous bottom surfaces 52are much easier to clean than compartmentalized or divided heatingchambers. Furthermore, the round body 29 of the latch 23 and thetranslation/rotation movement of the latch allow easy removal of thelids 27 from the lid holding tray 31 with one hand while positioning thelatch 23 to the unlocked position with another hand.

From a purely functional standpoint, a preferred latch 23 might simplyinclude a locking portion that is able to prevent inadvertentdisplacement of the lid 21 when the tray 27 is purposefully removed.Thus, a number of different configurations and shapes can be used forthe latch 23. The latch 23 illustrated here with the round body 29, onthe other hand, has an alternative, ornamental arrangement for the roundbody 29 in which the edges of the round body 29 include an arc-shaped,curved surface. This illustrated arrangement may add to the cost ofmanufacture, so the illustrated latch does not provide all of thepossible economic advantages that might be derived from the invention.On the other hand, this arrangement is believed to be aestheticallypleasing and is likely to be recognized and relied upon by purchasers toidentify the source of the food holding bin.

FIGS. 4A, 4B, and 5 are perspective views of an alternate embodiment ofa multi-zone food holding bin 10, the embodiment of FIGS. 4A, 4B, and 5including four separate food holding compartments 50. The embodiment ofFIGS. 4A, 4B, and 5 is substantially identical to the embodiment ofFIGS. 1-3 with the exception that the embodiment of FIGS. 4A, 4B, and 5includes four food holding compartments 50 instead of two, each foodholding compartment 50 including two food holding zones 57 a, 57 b, andeach food holding zone 57 a, 57 b including a single food holding bay 51a, 51 b, respectively. Thus, reference numbers identifying identicalelements are the same in FIGS. 1-3 and in FIGS. 4A, 4B, and 5 .Moreover, elements not illustrated in one of the embodiments areunderstood to be present in the other embodiment. For example, theembodiment illustrated in FIGS. 4A, 4B, and 5 includes cut-away viewsshowing internal components that are not visible in FIGS. 1-3 .Nevertheless, these internal components are understood to be present inthe embodiment illustrated in FIGS. 1-3 as well.

Similar to the embodiment of FIGS. 1-3 , each separate food holdingcompartment 50 in the food holding bin 10 of FIGS. 4A, 4B, and 5includes at least two separate food holding zones, a first food holdingzone 57 a and a second food holding zone 57 b. Each food holding zone 57a, 57 b is configured to maintain a different temperature. Of course, itis not necessary for the food holding zones 57 a, 57 b to be operated atdifferent temperatures in practice.

The bin 10 illustrated in FIG. 4A is sized, shaped and arranged to havefour compartments 50, however, bins in accordance with the disclosurecan have any number of compartments, including a single compartment.

In FIG. 4 , the first or top compartment is defined by the left andright sidewalls 30 and 35, the chassis top panel 20 and the first orupper-most shelf 52. The second compartment is defined by the twosidewalls 30 and 35, the shelf 52 for the first compartment and thesecond shelf 52. The third compartment is defined by the two sidewalls30, 35, the second shelf 52 and the third shelf 52. The fourthcompartment is defined by the two sidewalls 30 and 35, the third shelfand the chassis bottom 25.

The shelves 52, which partially define the compartments 50, are planaror at least substantially planar and supported in the chassis 15 attheir opposing side ends by the two chassis side walls 30 and 35. Eachshelf 52 forms a planar and continuous top surface, which defines aplanar and continuous bottom surface 53 of the compartment 50. Theplanar and continuous bottom surface 53 of the compartment is configuredto support food items (as mentioned above, the term “food item” includesbut is not limited to containers or trays containing food products suchas cooked protein patties, fried foods, and the like). Food items can beplaced onto the planar bottom surface 53 and removed from the planarbottom surface 53 through the open front face 40 or through the openrear face 45.

Each food holding bay 51 a, 51 b may include a dedicated display and/orcontrol 93 a, 93 b, respectively. Each display and/or control 93 a, 93 bmay display the temperature setpoint of a respective food holding bay 51a, 51 b, and in the embodiment illustrated in FIGS. 4A, 4B, and 5 , thetemperature of a respective food holding zone 57 a, 57 b. Moreover, eachdisplay and/or control 93 a, 93 b may control the respective heatingelements that maintain the temperature setpoint of the respective foodholding zones 57 a, 57 b. The displays and/or controls 93 a, 93 b may begrouped together (i.e., arranged horizontally beneath the respectivefood holding bay 51 a, 51 b) in the bezel 92 for a correspondingcompartment 50. In the embodiment illustrated in FIGS. 4A, 4B, and 5 , asingle bezel 92 is used to provide the display and/or control elementsfor a single compartment 50. The displays and/or controls 93 a, 93 b canprovide a graphical user interface to one or more controllers (notshown) for the bin 10.

Bin 10 control and control of the food holding zone 51 temperature iseffectuated in part by using one or more microcontrollers ormicroprocessors 97 in combination with temperature sensors 99. US2011-0114624 A1 entitled “Food Holding Cabinet Power Supplies withDownloadable Software,” the entirety of which is hereby incorporated byreference herein, discloses among other things, apparatuses and methodsby which compartments of a food holding bin can be controlled usingmicroprocessors having downloadable software.

Compartment temperature control is preferably effectuated using asemiconductor temperature sensor, thermally coupled to each food holdingzone 51 and electrically connected to a processor, such as thosedisclosed in US 2011-0114624 A1.

A semiconductor apparatus and method for measuring temperature of aplate or shelf in a food holding bin is disclosed in U.S. Pat. No.8,247,745, which is entitled “Temperature Sensor for a Food HoldingCabinet” the entirety of which is hereby incorporated by referenceherein.

The shelf 52 includes a lower heating element 67 for the first foodholding zone 57 a in a first or top food holding compartment 50, and anupper heating element 65 for a second food holding zone 57 b in a secondor lower food holding compartment 50, directly below the first foodholding compartment 50. While the first heating element 67 isillustrated as providing heat to the upper first food holding zone 57 a(from below) and the second heating element 65 is illustrated asproviding heat to the lower first food holding zone 57 a (from above),heating elements that are not shown include at least a heating elementthat provides heat to the upper first food holding zone 57 a from aboveand another heating element that provides heat to the lower first foodholding zone 57 a from below. Additionally, the second food holdingzones 57 b, which are adjacent to the first food holding zones 57 a, areheated in the same way as the first food holding zones 57 a, but withindependent heating elements. The heating elements of the second foodholding zones 57 b are independently controllable from the heatingelements of the first food holding zones 57 a. Referring to the insetFIG. 4B, the shelf 52 includes an upper thermally conductive plate,which forms the continuous planar bottom surface 53 of the first (orupper) food holding compartment 50 and a lower thermally conductiveplate, which forms a continuous planar upper surface 54 of the second(or lower) food holding compartment 50. The planar bottom surface 53 andthe planar upper surface 54 are spaced apart from each other by adistance sufficient to accommodate the inclusion of at least two heatingelements, which are illustrated in the figures as the separate firstheating element 67 and the separate second heating element 65,respectively. Again, the temperature of each food holding zone iscontrolled by independently controllable heating elements. Insulativematerials may be provided between the first heating element 67 and thesecond heating element 65 to provide better thermal control over thefood holding zones 57 a, 57 b. The first heating element 67 is a lowerheating element for the upper food holding compartment 50 and the secondheating element 65 is an upper heating element for the lower foodholding compartment 50.

The continuous planar bottom surface 53 of the top food holdingcompartment 50 and the continuous planar upper surface 54 of the bottomfood holding compartment are preferably made of aluminum, between aboutone-eighth and about one-quarter inch-thick. Alternate embodiments ofthe shelf 52 may use a thermally-conductive panel made of glass-ceramicor an ultra-low expansion glass for one or both of the lower surface 53and the upper surface 54.

Glass-ceramics and ultra-low expansion glass are considered herein to be“good” thermal conductors in that their conduction of heat energy islocalized. Such materials also make excellent shelves for a heated,multi-zone food holding bin because they permit localized areas of ashelf to be heated to a first temperature, without having the entireshelf reach the same temperature.

The first heating element 67 is disposed between the planar bottomsurface 53 and the planar upper surface 54 and the first heating element67 is in thermal communication with the planar bottom surface 53. Thefirst heating element 67 may be mechanically attached to the planarbottom surface 53 by a thermally-conductive adhesive, in one embodiment.The first heating element 67 may also be attached to the planar bottomsurface 53 by brackets or clamps.

The second heating element 65 is disposed between the planar bottomsurface 53 and the planar upper surface 54 and the second heatingelement 65 is in thermal communication with the planar upper surface 54.The second heating element 65 may be mechanically attached to the planarupper surface 54 by a thermally-conductive adhesive, in one embodiment.The second heating element 65 may also be attached to the planar uppersurface 54 by brackets or clamps.

In the embodiment illustrated in FIGS. 4A, 4B, and 5 , the first heatingelement 67 can be located above the second heating element 65 but inthermal communication with the planar bottom surface 53 such that whenthe temperature of the first heating element 67 rises, it provides heatenergy into the planar bottom surface 53 in a region around the firstheating element 67, and more specifically, within the first food holdingzone 57 a of the first or top food holding compartment 50. Thermallyinsulating the first heating element 67 from the planar upper surface 54and thermally insulating the second heating element 65 from the planarbottom surface 53, enables the first heating element 67 to provide afirst amount of heat energy into the planar bottom surface 53 (and thusinto the first food holding zone 57 a of the upper food holdingcompartment 50), while the second heating element 65 provides a secondamount of heat energy into the planar upper surface 54 (and thus intothe first food holding zone 57 b of the lower food holding compartment50). In this manner, each food holding zone 57 a, 57 b may be configuredto have an independent and unique temperature profile from top to bottomof the food holding zone 57 a, 57 b. For example, one food holding zone57 a, 57 b may have a temperature profile that generally decreases fromtop to bottom (i.e., the top of the food holding zone 57 a, 57 b ishotter than the bottom of the food holding zone 57 a, 57 b).

In some embodiments, the second heating element 65 may comprise aradiant heating source that projects radiant heat through the planarupper surface 54 and into the first food holding zone 57 a of the lowerfood holding compartment 50. In other words, in one embodiment, thefirst heating element 67 provides heat energy into the first foodholding zone 57 a of the upper food holding compartment 50 throughconduction, while the second heating element 65 provides heat energyinto the first food holding zone 57 a of the lower food holdingcompartment through radiation. Similarly, a radiant heating element maybe provided at a top interior surface of the first or top food holdingcompartment 50 beneath the chassis top panel 20. In this manner, the topand bottom of a food product placed into the first food holding zone 57a may absorb different amounts of heat energy, customized depending onthe type of food product. Thus, the heat profile in the first foodholding zone 57 a may be customized vertically as well as differentiatedfrom the heat profile in the second food holding zone 57 b. As a result,a single food holding compartment 50 (e.g., the upper compartment inFIGS. 4A and 5 ) may be customized to store different types of foodproducts in the first food holding zone 57 a and the second food holdingzone 57 b, each food holding zone 57 a, 57 b having a differenttemperature profile. As a result, the disclosed food holding bin 10 isflexible in that it can keep multiple different types of food productsat their ideal holding temperatures in a single food holdingcompartment, thus increasing efficiency and adaptability to differentfood demands.

Because of this flexibility, it has been found that a food holding binconstructed in accordance with the disclosure can extend thepalatability time of a food item by a factor of two or more.

An alternate embodiment, as illustrated in FIG. 6 , may use thethermoelectric effect provided by one or more Peltier devices 80 to heatone or more of the compartments 50.

The thermoelectric effect is a direct conversion of a temperaturedifference into an electric voltage and vice versa. When a voltage isapplied to a thermoelectric device, a temperature difference is createdacross the two sides of the device. The temperature difference createdin response to an applied voltage is known as the Peltier effect.Devices that produce temperature differences in response to an appliedvoltage are considered herein to be Peltier devices. A Peltier device 80is therefore considered herein to be a heat source or heating element.

Peltier devices have a “cold” side and a “hot” side. The cold sideabsorbs heat whereas the hot side emits heat. Heat emitted from the hotside includes at least some of the heat absorbed from the cold side. APeltier device 80 is therefore considered herein to be a solid-stateheat pump or heat-sinking device.

FIG. 6 is a cutaway view of another embodiment of a point-of-use holdingbin using Peltier devices to heat the food holding compartments 50. Inone embodiment, one or more Peltier devices 80 are “sandwiched” between,and in thermal communication with the bottom planar surface 53 and theupper planar surface 54 described above. Electrical energy is providedto the Peltier devices 80 through wires 85, under the control of acontroller.

“Sandwiching” the Peltier devices in a shelf 52 as shown in FIG. 6provides a shelf 52 cold on one side and hot on the other. Such a shelf52 structure thus enables a dual-mode food holding bin 10 having a“first” food holding compartment 50 that is warm and a verticallyadjacent “second” food holding compartment 50 that is cold.

Temperature control of a thermoelectric, Peltier device 80 may beaccomplished by controlling the electric energy provided to the device.Temperature control of one side of the Peltier device 80 can also beeffectuated by controlling heat transferred into or out of the oppositeside of the device, as described in US 2010-0307168 A1, entitled “ThermoElectric Cooler,” the disclosure of which is incorporated herein byreference in its entirety.

In another embodiment of a multi-zone food holding bin 10, multiplePeltier devices 80 are mounted between the bottom surface 53 and theupper surface 54 but have only their hot sides thermally coupled to thebottom surface 53 and to the upper surface 54. Air is then moved throughthe inter-plate space to heat the cool sides of the Peltier devicestherein.

Peltier devices as disclosed herein and similar heat transfer devicesare thermally coupled to the shelf 52, preferably by way of mechanicalattachment to at least one of the plates that form the lower planarsurface 53 and the upper planar surface 54. Mechanical attachment andthe resultant thermal coupling is preferably accomplished by athermally-conductive adhesive, however, clamps that are attached to aplate by screws driven into a plate can also be used.

The shelves are mechanically coupled to the side panels 30 and 35. Theside panels are also preferably made from thermally-conductive materialsuch as aluminum. Thermally coupling a heat transfer device to one ormore plates that comprise a shelf therefore also thermally couples theheat transfer device to the side walls and thus to the compartment. Heattransfer devices coupled to a shelf are therefore also thermally coupledto the corresponding compartment.

While the temperature of a Peltier device can be controlled bycontrolling the heat dissipated from the hot side and/or the heatabsorbed into the cold side, bin embodiments

disclosed herein preferably control compartment temperature using one ormore semiconductor temperature sensors, thermally coupled to one or moreof the thermally-conductive structures that comprise a compartment. Binembodiments disclosed herein preferably use a semiconductor temperaturesensor that is directly coupled and therefore thermally coupled to theheated surfaces 53 and/or 54 provided by the shelves 52.

Semiconductor temperature sensors used in preferred embodimentsdisclosed herein are disclosed in U.S. Pat. No. 8,247,745, which isentitled “Temperature Sensor for a Food Holding Cabinet” the entirety ofwhich is hereby incorporated by reference herein, especially theteachings of the structure and use of a semiconductor temperaturesensor.

Thus, suitable heating elements for use in accordance with thedisclosure include electrically-resistive heating elements, such asheated coils, radiant heating elements that provide heat energy viaradiation, and devices and ancillary equipment that provide heat to aworking fluid. As described above, Peltier devices may also be used asheating elements in accordance with the disclosure.

The foregoing description is for purposes of illustration only and notfor purposes of limitation. The true scope of the invention is set forthby the appended claims.

The invention claimed is:
 1. A method of maintaining differenttemperatures within a multi-zone food holding bin, the multi-zone foodholding bin comprising a chassis having a top panel, a first side panel,a second side panel, a bottom panel, and a font face, the multi-zonefood holding bin having a first food holding compartment within thechassis and comprising a first food holding zone and a second foodholding zone, the first food holding compartment being defined by thefirst side panel, the second side panel, the top panel that provides afirst top surface, and a first substantially planar bottom surface of athermally conductive material being substantially unobstructed betweenthe first side panel and the second side panel and a first openingthrough the front face configured to allow a tray for food items to bepassed through the first opening into the first food holding compartmentand onto the first substantially planar surface and a second foodholding compartment within the chassis and comprising a third foodholding zone and a fourth food holding zone, the second food holdingcompartment being defined by the first side panel, the second sidepanel, the bottom panel that provides a second substantially planarbottom surface of a thermally conductive material, and a second topsurface, the second substantially planar bottom surface beingsubstantially unobstructed between the first side panel and the secondside panel and a second opening into the second food holding compartmentand onto the second substantially planar surface, the method comprising:operating the first food holding zone to a first temperature setpoint byindependently operating a first heating element in the first foodholding zone and thermally coupled to the first top surface andindependently operating a second heating element in the first foodholding zone and thermally coupled to the first substantially planarsurface; operating the second food holding zone to a second temperaturesetpoint by independently operating a third heating element in thesecond food holding zone and thermally coupled to the first top surfaceand independently operating a fourth heating element in the second foodholding zone and thermally coupled to the first substantially planarsurface; operating the third food holding zone to a third temperaturesetpoint by independently operating a fifth heating element in the thirdfood holding zone and thermally coupled to the second top surface andindependently operating a sixth heating element in the third foodholding zone and thermally coupled to the second substantially planarsurface; and operating the fourth food holding zone to a fourthtemperature setpoint by independently operating a seventh heatingelement in the fourth food holding zone and thermally coupled to thesecond top surface and independently operating an eighth heating elementin the fourth food holding zone and thermally coupled to the secondsubstantially planar surface; wherein the first temperature, secondtemperature, third temperature, and fourth temperature are independentfrom each other.
 2. The method of claim 1, wherein the multi-zone foodholding bin further comprises a shelf disposed between the first sidepanel and the second side panel, wherein a top surface of the shelfprovides the first substantially planar bottom surface and a bottomsurface of the shelf provides the second top surface.
 3. The method ofclaim 1, wherein the multi-zone food holding bin further comprises athird food holding compartment within the chassis between the first foodholding compartment and the second food holding compartment, the thirdfood holding compartment comprising a fifth food holding zone and asixth food holding zone, the third food holding compartment beingdefined by the first side panel, the second side panel, a third topsurface, and a third substantially planar bottom surface of a thermallyconductive material being substantially unobstructed between the firstside panel and the second side panel and a third opening through thefront face configured to allow a tray for food items to be passedthrough the third opening into the third food holding compartment andonto the third substantially planar surface, the method furthercomprising: operating the fifth food holding zone to a fifth temperaturesetpoint by independently operating a ninth heating element in the fifthfood holding zone and thermally coupled to the third top surface andindependently operating a tenth heating element in the fifth foodholding zone and thermally coupled to the third substantially planarsurface; and operating the sixth food holding zone to a sixthtemperature setpoint by independently operating an eleventh heatingelement in the sixth food holding zone and thermally coupled to thethird top surface and independently operating a twelfth heating elementin the sixth food holding zone and thermally coupled to the thirdsubstantially planar surface.
 4. The method of claim 3, wherein themulti-zone food holding bin comprises a first shelf disposed between thefirst side panel and the second side panel and between the firstcompartment and the second compartment, wherein a first top surface ofthe first shelf provides the first substantially planar bottom surfaceand a first bottom surface of the first shelf provides the third topsurface, and the multi-zone food holding bin further comprises a secondshelf disposed between the first side panel and the second side paneland between the third compartment and the second compartment, wherein asecond top surface of the second shelf provides the third substantiallyplanar bottom surface and a second bottom surface of the second shelfprovides the second top surface.
 5. The method of claim 1, furthercomprising: receiving a first tray of a first food product through thefirst opening into the first food holding zone; receiving a second trayof a second food product through the first opening into the second foodholding zone; receiving a third tray of a third food product through thesecond opening into the third food holding zone; and receiving a fourthtray of a fourth food product through the second opening into the fourthfood holding zone.
 6. The method of claim 5 wherein the multi-zone foodholding bin comprises a rear face and the method further comprises:providing a third opening through the rear face configured to allow thefirst or second tray to be passed through the third opening into thefirst food holding compartment and onto the first substantially planarsurface; and providing a fourth opening through the rear face configuredto allow the third or fourth tray to be passed through the fourthopening into the second food holding compartment and onto the secondsubstantially planar surface.
 7. The method of claim 6, furthercomprising: receiving a tray of the first, second, third, and fourthtrays, when said tray is filled with freshly cooked food product,through the respective third or fourth opening; and receiving the trayof the first, second, third, and fourth trays, when food product hasbeen removed from said tray, through the respective first or secondopening.
 8. The method of claim 1, wherein the multi-zone food holdingbin comprises a plurality of bays, the plurality of bays comprising afirst bay and a second bay within the first food heating zone, a thirdbay and a fourth bay within the second food heating zone, a fifth bayand a sixth bay within the third food heating zone, and a seventh bayand an eighth bay within the fourth food heating zone, wherein each bayof the plurality of bays is configured to receive a tray of foodproduct.
 9. The method of claim 8, further comprising plurality of lidholding shelves, a lid holding shelf of the plurality of lid holdingshelves associated with each bay of the plurality of bays, wherein eachlid holding shelf is configured to receive a lid thereon.
 10. The methodof claim 9, further comprising: receiving a first lid through the firstopening into the first bay of the first food holding zone; and retainingthe first lid within the first bay on the lid holding shelf associatedwith the first bay.
 11. The method of claim 10, further comprising:receiving a first tray of a first food product through the first openinginto the first bay of the first food holding zone onto the firstsubstantially planar bottom surface below the first lid; receiving asecond tray of a second food product through the first opening into thesecond bay of the first food holding zone onto the first substantiallyplanar bottom surface; and maintaining, with the first lid, an increasedmoisture within the first tray compared to a moisture within the secondtray, while operating the first bay and the second bay of the first foodholding zone to the first temperature setpoint by independentlyoperating the first heating element and the second heating element. 12.The method of claim 9, wherein at least some of the lid holding shelvesof the plurality of lid holding shelves downwardly depend from the firsttop surface towards the first substantially planar bottom surface,leaving the first substantially planar bottom surface substantiallyunobstructed between the first side panel and the second side panel. 13.The method of claim 12, further comprising providing a latch associatedwith at least one of the lid holding shelves, the latch movably securedto the front face.
 14. The method of claim 13, further comprisingbiasing the latch into a position that retains a lid on the associatedlid holding shelf with gravity.
 15. The method of claim 14, furthercomprising providing a bezel set forward of the front face to form a gapbetween the front face and the bezel, wherein the latch moves within thegap.
 16. The method of claim 1, further comprising receiving a userinput of the first temperature setpoint.
 17. The method of claim 16,wherein the user input is a user selection of a food item for the firstfood holding zone, wherein the user selection of the food item isassociated with independent operation and control of the first heatingelement and the second heating element.
 18. The method of claim 17,further comprising operating the first heating element to output moreheat than the second heating element.
 19. The method of claim 17,further comprising operating the second heating element to output moreheat than the first heating element.
 20. The method of claim 16, furthercomprising: providing a bezel set forward of the front face, the bezelcomprising a user interface; and operating the user interface to receivethe user input.